Rotavirus particles were originally identified in 1974 in stool specimens by electron microscopy (Bishop et al, "Detection of a new virus by electron microscopy of faecal extracts from children with acute gastroenteritis." Lancet, 1974, 149).
Rotaviruses are now recognised as an important cause of severe acute diarrhoea in young children throughout the world. After the initial identification of rotaviruses as causative agents of actue diarrhoea, efforts were made to culture them in a wide variety of cell lines without much success.
Human rotaviruses have been broadly classified into two groups, those with "short RNA" (S) patterns and those with "long RNA" (L) patterns, based on the mobility of their RNA genome segments upon gel electrophoresis.
In 1981, Sato et al described successful cultivation of human rotaviruses from faecal specimens using roller cultures of MA-104 cells; "Isolation of human rotavirus in cell cultures." Arch. Virol. 69:155-160. Specimens were pretreated with trypsin and small amounts of trypsin were incorporated into the maintenance medium. The technique has been used successfully by others to culture rotavirus strains from diarrhoeal stools.
The majority of strains so far grown are those with the "L" patterns. "S" pattern strains have proved difficult to grow and successful cultivation of only two strains of rotavirus with "S" patterns has been described to date (for example, in 1982 by Kutsuzawa et al, "Isolation of human rotavirus subgroups 1 and 2 in cell culture." J. Clin. Microbiol. 16:727-730).